With a massive integration of distributed renewable energy resources such as wind and photovoltaic, traditional distribution networks have been developing as active distribution networks. In the active distribution network, massive distributed renewable energy resources are integrated such that the electric energy production changes quickly and randomly over time. Traditionally, a transmission network and a distribution network are optimized independently, in which the distribution network is equal to a load node in the transmission network, and the transmission network is equal to an electric generator balance node in the distribution network.
However, in the active distribution network, it is disadvantageous in that: (1) the massive distributed renewable energy resources lead to the strong randomness of the distribution network and there is a tight coupling between the distribution network and the transmission network, such that an independent reactive power control mode will cause a huge amount of power mismatch loss at the boundary of the transmission and distribution network; (2) since there is a massive integration of distributed renewable energy resources in the distribution network, there will be a problem such as overvoltage at a power injection node, and the distribution network needs a cooperation with the transmission network to eliminate the overvoltage; (3) for the transmission and distribution network, there is a lack of coordination between the transmission network and the distribution network, which is unable to ensure an optimal economic objective for the transmission and distribution network.